Saturday, 31 January 2015

Skoda Production Status

As with German factories that fell into the Soviet zone of influence, the Soviets took inventory of other factories working for Germany, to figure out if anything they produced was of value to them. I already posted the results of this assessment.

"Note on the condition of tank production at Skoda factories

1. G-13 tank destroyers
Current production batch: 2000 tanks
Supplied to former German military directorate: 800
Remaining tanks still in production: 1200

Of those, 150 tanks can be assembled in a short amount of time (about 6 months). The rest (1050 tanks) are currently in production, with parts being produced here or by subcontractors. According to preliminary data, these 1050 tanks are 45-60% complete. The exact degree of completion is currently being established.

78 7.5 cm guns are available to arm these tanks, the rest would have to be manufactured. There are no machineguns, as the machineguns were supplied by the buyer.

2. Tiger Assault Tanks

We produced certain components for the Nibelungenwerke company. This order was completed before the end of the war.

3. Hulls and turrets for the heavy Tiger II tank

The initial order for 300 hulls and 300 turrets by OKH made on September 17th, 1943, was reduced to 86 hulls and 103 turrets on March 13th, 1945.

As of April 19th, 1945, 15 hulls and 10 turrets were ready at the Hradec Králové factory, but they were not delivered to the German military directorate.

In July of this year, the Red Army accepted the following at Hradec Králové:
  • 19 fully or partially completed Tiger II hulls.
  • 19 fully or partially completed Tiger II turrets.
and the remainder of unprepared materials, as a result of which, the order was completed."

Friday, 30 January 2015

SU-152 with A-19

We've seen the idea of mounting an A-19 gun on a SU-152 before, but the plan was never actually implemented. Here is another iteration, with a little more reasoning.

"To the member of the Military Council of Armoured and Mechanized Forces of the Red Army, Lieutenant-General of the Tank Forces, comrade Biryukov

I report my ideas on the topic of armament of the SU-152 (on the KV chassis). The existing SU-152 SPG has one drawback along with many of its positive qualities, specifically that the ML-20 152 mm gun is basically a howitzer. As a result, when shooting at long ranges, on the order of 2000 meters, the angle of elevation is high and the target is no longer within the field of view of the sight.

Along with the 152 mm ML-20 gun, NKV factories produce the 122 mm A-19 gun, whose oscillating part is identical to the ML-20's. The A-19's shell has a flat trajectory, and the penetration of the gun is greater than that of any other gun used by the Red Army.

I think that it is reasonable and necessary to arm half of produced SU-152s with 122 mm guns. This will allow the SPGs to freely combat any existing enemy armoured vehicles at long ranges.

No design changes are necessary. All that must be done is the 152 mm barrel should be exchanged for a 122 mm one and new 122 mm ammunition racks should be installed.

I ask you to support my request to the director of the Kirov factory to produce one prototype of a SU-152 with a 122 mm A-19 gun. This SPG must undergo gunnery trials and the results of the trials will decide whether or not the tanks will be re-armed. The Kirov factory already has A-19 guns.

Chief of the GBTU Tank Directorate, Engineer-Colonel Afonin
Deputy Chief of the 6th Department of the Tank Directorate, Engineer-Major Voroshilov"

CAMD RF 38-11355-1401

Thursday, 29 January 2015

Damage to T-70s

Just as with the document on T-34s from many months ago, the Red Army also needed to know how its meeker cousin, the T-70, was doing.

"Examined T-70 tanks can be split into two major groups:
  1. Tanks that were knocked out without armour penetrations, due to a broken engine, suspension damage, etc.
  2. Tanks that were knocked out with armour penetration, as a result of artillery, machinegun, or mortar hits, or due to being blow up with mines or bombs.
Of the 70 examined T-70 tanks, 12 belong in the first group (17.2%) and 58 to the second (82.8%). The percentage of tanks knocked out due to the first category is high, and means that quality of internal mechanisms and the suspension should be increased.

The losses in the first category are caused as follows:
  1. Damage to the engine or transmission: 9, or 75%
  2. Fire: 2, or 16.5%
  3. Suspension damage: 1, or 3.5%
It can be seen that the leading cause of breakdowns is damage to the engine or transmission.

On the 58 tanks knocked out by armour penetration, the following damage was detected:
  1. 141 hits to the hull, or 66.5%
  2. 71 hits to the turret, or 33.5%
The damage can be split into two groups: penetrating hits and nonpenetrating hits.
  1. Nonpenetrating shots: 65, or 30.7%
  2. Penetrating shots: 147, or 69.5%
i.e. two thirds of hits to the T-70 penetrate.

Table #1 shows the distribution of hits from all calibers to all components.

Hits from all calibers
Hits per caliber
Up to 50 mm
More than 50 mm

As can be seen from Table #1, the main method of fighting T-70 tanks is artillery with a caliber of 50 mm or lower. As Table #2 shows, this artillery is very effective, with 63.5% of the hits being penetrations."

The report is quite lengthy, so I'm going to skip over some parts and discuss the quality of the armour, like I did with the T-34. The first thing to look at is the strongest part of the armour, the upper front plate.

Damage Type
Damage from all calibers
Breakdown by caliber
Up to 50 mm
Over 50 mm
Breach and crack
This part of the tank is pretty decent at deflecting shots, bouncing two thirds of shells 50 mm and smaller and about half of shells bigger than 50 mm. Unfortunately, these overmatching calibers do cause breaches and cracks occasionally, although the sample size is small.

Next, the sides.

Damage Type
Damage from all calibers
Breakdown by caliber
Up to 50 mm
Over 50 mm
Breach and crack

The sides are very thin, so literally everything overmatches them. However, they manage to bounce a few shots from low calibers. Calibers over 50 mm are naturally going to wreck the armour quite a bit, but the amount of "clean" penetrations is still much greater than "ragged" ones. 

Turret side:

Damage Type
Damage from all calibers
Breakdown by caliber
Up to 50 mm
Over 50 mm
Breach and crack
The side of the turret is is doing much better than the hull, with a high chance of ricochet and a very low chance of breaches. Despite the significant sample size, there are no cracks at all. Very nice!

The front of the turret has a very small amount of samples, but it also manages to not crack. 

Tuesday, 27 January 2015


Since today is the 70th anniversary of the liberation of Auschwitz, there have been a number of speeches made on the topic. Unfortunately, the authors of those speeches didn't seem to be particularly well read, and one mistake exists among many of them: the idea that the 1st Ukrainian Front that liberated the camp was composed entirely of Ukrainians. Thankfully, the Ministry of Defense put up a number of documents associated with the liberation, one of which was a demographic overview of the unit involved in the battle for the camp, the 60th Army. Here is a page from it, listing the nationalities of soldiers, NCOs, and officers.

Out of 11374 officers, 7501 or 66% were Russian, and 2126 (19%) were Ukrainian. These nationalities the vast majority of the personnel, as the next highest (Belarusians) nationality is only at 311 officers (3%). Out of 22321 NCOs, 12603 (56%) were Russian, 7568 (34%) were Ukrainian, and 353 (1.5%) were Belarusian. Among privates, the numbers are a bit different, with 28347 Ukrainians (51%) out of 55848, 22294 Russians (40%) and 546 Belarusians (1%). 

Aside from nationalities, the document contains many interesting statistics. For instance, education. Most officers are well educated (1907 have 1-6 grades of school, 4080 have 7-9 grades, and 5387 have secondary or post-secondary education), but 20 NCOs have no formal education (127812 have 1-6 grades, 8642 have 7-9 grades, and 2300 have more), and 8962 privates have no formal education, 41472 have 1-6 grades, 8642 have 7-9 grades, and 1772 have more than that.

2388 out of the army's total number were women (1081 privates, 751 NCOs, and 556 officers and specialists). A rather significant amount (57 officers, 101 NCOs, and 1208 privates) were born in 1893 or earlier, so they were old enough to fight in WWI and would have been at least 52 when this document was written. More privates (7244) were born after 1924, more than any other age range. NCOs were also mostly from that range (3620), but officers were a little older. Among them, 1919-1921 dominated (1721).

This document and many others are available in the Ministry of Defense Media Library.

According to Krivosheev's calculations summarizing the demographics from January 1st, 1943, 1944, and 1945, this was the composition of the Red Army broken down by nationality:

Russians 66.402
Ukrainians 15.890
Belarusians 2.917
Tatars 2.165
Jews 1.644
Kazakhs 1.448
Uzbeks 1.360
Armenians 0.966
Georgians 0.917
Mordovinians 0.730
Chuvashes 0.730
Azerbaijani 0.673
Moldavians 0.621
Baskirs 0.366
Kirghiz 0.307
Udmurt 0.268
Tajiks 0.264
Turkmen 0.246
Estonians 0.245
Mari 0.241
Buryats 0.150
Komi 0.134
Latvians 0.134
Lithuanians 0.134
Peoples of Dagestan 0.128
Ossetians 0.123
Poles 0.117
Karelians 0.110
Kalmycks 0.046
Kabardians and Balkarians 0.039
Greeks 0.028
Chechens and Ingush 0.026
Finns 0.018
Bulgarians 0.013
Czechs and Slovaks 0.005
Chinese 0.005
Yugoslavians 0.001
Other 0.389

Tank Tracking

"In order to increase efficiency, I propose that, starting on January 1st, 1945, additional fuel tanks will be collected from all destroyed tanks.

Report to the URT chief on the 1st and 15th of every month with the number of tanks collected, and send them to the destinations in his reply.

At the same time, the following procedure is implemented regarding additional tanks on tanks that leave major repairs:
  1. Tanks that are sent for repairs from fronts, districts, and academies must have additional tanks present. Record the presence of additional tanks.
  2. Tanks that were sent for repairs without additional tanks will be returned to fronts, districts, and academies without additional tanks."

Monday, 26 January 2015

4th Guards Tank Brigade in the Berlin Offensive Operation

The following vehicles were in possession of the 4th Guards Army as of April 10th, 1945 (CAMD RF 236-2673-2714).

Engine-hours expended in functional vehicles
Vehicles that worked past the warranty limit









Most of these vehicles are running on V-2 variants, aside from the few oddballs: SU-57 (M2 halftrack with 57 mm AT gun), MK-9/10 (late Valentine modification), and SU-76s which run on a pair of car engines. 

There are also 10 tanks and 5 SPGs in light repairs, 24 tanks and 4 SPGs in medium repairs, and 26 tanks and 14 SPGs in major repairs, with a total of 83 vehicles undergoing repairs for all reasons.

Plan of the Berlin Offensive Operation 

After this information is gathered, the Army is thrown into the Berlin Offensive Operation. Tanks outpace infantry in deep, bold offensives to encircle the enemy, but, perhaps more importantly, reach Berlin first. A panicked note from Konev read: "Zhukov's forces are within 10 km of Berlin. You must reach the city first, at any cost." 

The 4th Guards Tank Army gets no rest. After Berlin fell, they have a new objective: eliminate the enemy forces in Czechoslovakia, so another inventory is taken. As of May 6th, the beginning of the offensive, the Army has 309 total tanks remaining in fighting condition: 203 T-34-85s, 3 T-34-76es, the one Valentine, 17 IS tanks, 30 SU-57s, 20 SU-76, 6 SU-85, 19 SU-100, 2 SU-122, and 8 ISU-122. 8 vehicles were undergoing light repairs, 48 were undergoing medium repairs, and 29 undergoing major repairs. This figure is not much greater than at the beginning of the Berlin Offensive Operation (only two additional vehicles). 11 tanks have been cleared out of the major repairs category (quite a feat, as a major repair is a total replacement of all components and is estimated to take 1600 man-hours, and even that is at a factory and not in the field). The light repair category has shrunk in half, but the medium repairs category has grown by 20 units from 28 to 48. A medium repair consists of a replacement of several assemblies, so it takes in tanks that are pretty beat up. If many tanks fall into the medium repairs category, either they have taken many hits in combat or have had many components worn down, without any specific one being a limiting factor.

The fighting force of the Army has been reduced considerably during this operation, from 412 tanks to 309. Of course, these losses weren't for nothing, as the Army destroyed the following during the course of the operation (April 16th-May 3rd):

Tanks and SPGs: 285
Guns of various calibers: 589
APCs: 225
Cars: 1562
Machineguns: 869
Mortars: 339
"Six-barreled mortars" (Nebelwerfers): 19
Motorcycles: 251
Radios: 4
Airplanes: 35
Carts: 1730
Convoys with military goods: 5
Telephone-telegraph stations: 1
Motorboats: 13
Bicycles: 2000
Rifles and submachineguns: 2500
Military warehouses: 40
Soldiers and officers: 42855

In addition to the destroyed items, the Army captured the following:

Tanks and SPGs: 25
Guns of various calibers: 62
APCs: 21
Motorcycles: 236
Cars: 1877
Machineguns: 622
Rifles and submachineguns: 6604
Airplanes (functional): 227
Airplanes (nonfunctional): 265
Locomotives: 57
Train cars: 2507
Airports: 5
Aircraft engines: 362
Airplane bombs: 3000
Parachutes: 1000
AA gun shells: 124000
Mortars: 188
Bicycles: 1300
Barges: 2
Military warehouses: 319
Factories and workshops: 110
Soldiers and officers: 31350

In addition, 38620 prisoners of war, including 10000 Soviet citizens, were liberated.

Sunday, 25 January 2015

Stalin Shutdown

The opinion that Stalin was somehow all-powerful and nobody dared refuse his requests. However, that is not true. Here is a response to a request for 45 mm guns for Stalin's pet KV-7 project.

"To the Deputy People's Commissar of Tank Production, comrade Zaltsmann
On the issue of delivery of 45 mm guns for coaxial mounts.

The production of 45 mm guns in coaxial mounts for KV tanks is not mentioned in any GKO decree. Therefore, the requested 45 mm guns will not be sent to the Kirov factory (ChTZ).

Deputy Chief of Red Army GAU, Major-General of Artillery, Hohlov
Military Commissar of the Red Army GAU, Divisional Commissar Novikov"

CAMD RF 81-12104-422

After spelling out "get bent" in two entire paragraphs, nobody ended up getting shot.

Saturday, 24 January 2015

World of Tanks History Section: Kolchigin's All in One

In the 1930s, Soviet military minds carefully watched the civil war unfolding in Spain, read reports and articles by foreign analysts. Both agreed on one thing: tanks with no infantry were capable of only fruitless effort and occasional local gains.

Divisional Commander Kolchigin, a lecturer at the Frunze Military Academy, proposed an original vision of future tanks. No more wasted effort and minor gains, only success and victory! How did Kolchigin's futuristic tanks look?

Jack of all Trades
Kolchigin's tank was meant for independent mechanized units, "creating their own operational weather". Independent meant autonomous, relying on as little support as possible from other vehicles. But how can this be achieved? You cannot make the tank too large, or it will be an easy target. What yo ucan do is make mechanisms smaller, reduce the length of the crankshaft, and place the engine in the front of the tank. This way, minor repairs can be done without leaving the tank.

In order to increase mobility and autonomy, the tanks must be able to switch from tracks to wheels and back without the crew leaving the tank. Mechanized shovels and saws would help the vehicle create trenches and construct obstructions for the enemy. If the tank was amphibious, there would be no need for bulky pontoons. In order to deal with breakdowns during marches, the tanks would have "a manner of bumper on the front and back" which could hook the tanks together and let one tow another.

A crew of three could not effectively observe the battlefield and tired quickly. Kolchigin proposed a 6-8 man crew, which would also make motorized infantry or "motorized sappers" unnecessary. A part of the crew could simply leave the tank to take prisoners, demolish bridges, etc. If the crew can take turns sleeping inside the tank, then tankers would be tired less, and would be able to perform more repairs on their own, reducing the need for repair units. The tank would be controlled by either the driver or the commander. A similar mechanism already existed on aircraft.

These tanks, in Kolchigin's vision, would fight for extended periods of time with limited supplies. Because of this, a short 76 mm gun and a "powerful machinegun" that could double as an AA gun would be sufficient. As a result, AA forces could be reduced. The tank would have 3-4 submachineguns and grenades for defense from infantry. The inventor considered it mandatory to have the ability to provide indirect fire, so that the tanks could perform artillery barrages without the aid of towed guns. Kolchigin considered self propelled artillery insufficiently effective. Since ammunition could run out during these long operations, the tank's ramming capability would be reinforced.

In order to reduce time spent on supplies and fueling, these tanks would be supplied on the move by a supply tank. This tank would have "very thin" armour, and be armed with a "powerful machinegun", a submachinegun, and two rifles with grenade launchers. These launchers would have HEAT grenades to fire at enemy tanks. The supply tank would carry all manner of supplies, and could also be modified to spray poisonous gases or lay mines. The tank could also be equipped with a 8-9 inch mortar with a range of 2-3 kilometers to destroy enemy fortifications.

Commander in Chief
Kolchigin devoted special attention to a future commander tank. The author remarked that modern radios are either insufficiently powerful or too large. If placed in a truck or an armoured car, they fall behind. Would it not be simpler to put all staff in special "battle radiotanks" with expert drivers?

Kolchigin's commander tank would be more maneuverable and faster than a regular one, since the commander would have to relocate often. The author made a reasonable comment that the tank should look as similar as possible to a regular tank, as commanders' vehicles would draw fire.

The commander's tank would have a whole communications center with 5 radio stations. They would communicate with the subordinates, superior HQ, aircraft, and rear units. In order to observe the battlefield, the tank would be equipped with a small unmanned airplane. Information from the airplane and others like it would be transmitted to the commander's television. The complicated problem of communication was solved very elegantly, as Kolchigin thought.

The inventor cared about the commander's comfort. He wanted the workspace to be free of noise or shaking. The commander needed a desk and a place to rest.

In order for the commander to not die in a reconnaissance mission, radio controlled tanks would be used.

Ideal Utopia
Kolchigin wanted all types of tanks to share a chassis. The annoyance of having to deal with many types of vehicles was very noticeable. Armies of the world came to the same conclusion, but much later.

Accordin to Kolchigin, this futuristic tank army would also include the benefits of artillery and infantry. So, how many tanks should it have? Intelligence reported that a German division had 500 tanks. Kolchigin composed his division of 20 battalions of 48 tanks each, or 960 tanks in total, excluding the ones assigned to HQ.

The proposal seems utopic even for the 21st century. Tanks that automatically exchange wheels for tracks, rammer tanks, tanks with televisions that control UAVs? Tanks carrying 10 men that need no sappers, AA guns, artillery, or motorized infantry?

Paradoxically, despite the fantasy of transformer tanks with five radios, Kolchigin's ideas were individually already being implemented. There were planes that could fuel up in the air, tanks and planes that could be controlled by radio, television. However, assembling all this together would be impossibly difficult.

The author was very realistic about the technical problems with his wonder-tanks, and stated that "the familiarization of tank designers with this work will definitely raise a number of questions in their field". You cannot argue with that statement.

Source: RGVA 31811-4-28

Original article available here

Author: Evgeniy Belash

Evgeniy Belash is a historian, an author of books and articles on the First and Second World Wars. His best known work is "Myths of the First World War". He is the author of a book "Tanks of the Interbellum" on the participation of armoured vehicles in military conflicts in the 1920s and 1930s.

Friday, 23 January 2015

Arming the Russian Renault

"An Act of Artillery Trials

The current act is composed to record that, on November 9th, 1920, a 37 mm Hotchkiss gun #124 produced in 1895 and converted by the Sormovo factory according to blueprint #31138, installed on Renault tank #2 produced at the Sormovo factory, underwent trials.

11 shots were fired with combat rounds. The results were satisfactory. After trials, the Renault type gun mount with modifications assembled at Sormovo was disassembled, examined, and judged to be free of defects.

Short history of the production of the first tank in Russia. Practical time requirements:

The blueprints for the chassis were made at Sormovo, and engines by AMO, by January 1st, 1920. Production work started in February of 1920. Armour arrived at Sormovo in June, engines in July. Assembly of the first tank finished in August of 1920. Initial trials revealed many design and manufacturing defects. Two months, September and October, were necessary to correct those defects. Full trials were carried out by the Council of Military Industry in November.

The shipment of the first tank is planned for December 15th. After that, four per month will be delivered, with the order being finished in March of 1921. As such, the assembly of all 15 tanks took place from October 1919 to March 1921, of those:
  • Preliminary work took 5 months
  • Production took 10 months
  • Trials and conversions took 3 months.
Total: 18 months.

As a result of SVP trials from November 13th to November 21st, it was determined that the tank meets requirements and is a reliable combat unit."

Thursday, 22 January 2015

MS-1 Improvements

"On June 20th, 1927, conclusions #1832 of the technical commission on the Technical Subcommission on the Trials of the Support Tank arrived at the Bolshevik factory.

Based on the results, the Technical Subcommission considers it possible to accept the proposed system as the basis for production of Support Tanks, under the conditions that the following improvements are made by the Armament Arsenal Trust:
  1. Engine:
    1. Install the carburettor defined in the technical project.
    2. Install a reverse valve on the gas tank caps, restore the ability to self-supply the fuel as defined in the technical project, make the fuel pump more convenient to use.
  2. Transmission:
    1. Establish the gear ratios that enable the tank to handle a 35 degree grade forward and 40 degree grade backward, with a maximum speed of 16 kph in third gear and 20 kph in fourth gear when using second grade Baku gasoline and regular oil.
    2. Reduce the heating up of the brakes over long periods of use. Allow the tank to drive in a curve of any radius without jerking on turns, and make the brakes more convenient to regulate.
  3. Controls:
    1. It is desirable that the driver's pedals be moved forward, allowing him to sit in a more natural position.
    2. Instead of stoppers on the brake levers, experiment with a stopper on the brake pedal, similar to the stopper on the accelerator pedal.
    3. Install a safety that prevents accidental setting of the reverse gear when shifting from first gear.
  4. Electric equipment:
    1. Install an additional battery or dynamo generator for starting the tank, preserving the ability to start it from the inside or outside.
    2. Prevent the wiring from being destroyed by oil and hot walls of the engine housing, preventing the possibility that the sparkplugs arc and add an engine off switch.
    3. Add a lamp next to the manometer and thermometer, and add an outlet for a portable lamp and removable front headlight.
  5. Suspension:
    1. Increase the width of a crossable trench to 1.8 meters.
    2. Equip the idler disk and rim with openings to clean out dirt that is stuck between the tracks and idler.
    3. Prevent the sticking of the springs in the carrier housing.
    4. Prevent the destruction of the pin that holds the gear in the balancer.
    5. Test trapezoidally segmented tracks instead of the current rectangular ones to reduce the wear of the rims.
    6. Protect vulnerable portions of the idler and drive wheel with armour.
  6. Armour:
    For subsequent tanks:
    1. Provide individual armour plates of the specified thickness and robustness for ballistic testing.
    2. Agree on the final position of the observation slits with the Artillery Committee.
    3. The next tank needs to have a waterproof hull up to 800 mm, and measures should be taken to make it gas-proof.
  7. Armament:
    1. Replace the existing 37 mm Hotchkiss gun with a normal one whose bore axis passes through the center of the turret, and has an independent horizontal traverse of at least 10 degrees.
    2. Equip the turret with a stopper for firing. 
Additionally, the Armament Arsenal Trust needs to implement all changes that are deemed necessary after engine trials, and after the inspection of a tank after field trials. At the end of field trials, the Trust must supply a tank for trials with tracks that have two more track links."

Wednesday, 21 January 2015

Tank Production at CKD, 1941

"Resident agent information on tank production at CKD (Prague-Liben)

1. Tank production

CKD produces 38(t) light tanks (A sample is available at the Red Army GABTU proving grounds. See a complete description in Tanks, Armoured Cars and Auxiliary Vehicles of Germany RU KA 1941) for Germany, which are used in large numbers in the war against the USSR. Currently, 15-20 tanks are produced per week. Tanks are sent to a military arsenal in Vienna. Each month, 60 tanks are sent.

According to data that needs to be verified, 1800 38(t)s have been ordered by Germany. As of September 1st, 1941, 972 have been produced.

CKD also supplies the front with spare parts. 3-4 train cars of parts for 38(t) tanks including assemblies (engines, gearboxes, etc) are sent every week. As of August 11th, 50 engines were sent, several of which have been removed from finished tanks. A part of the engines are delivered by aircraft. On August 21st, 9 tanks were sent from the factory with no engines.

A small number of 38(t) tanks was ordered by Slovakia. Slovakia received 10 tanks so far. 20 more tanks are currently being assembled, but it is not known if they will be delivered.

The factory can sustain a tempo of 50-60 tanks per month with difficulty, in part due to problems with subcontractors. The biggest difficulty is with electrical equipment, supplied by Germany.

2. Tank repair

As of September 1st, 106 tanks were repaired at CKD, not including tanks repaired by specialists in the field.

In the end of August, 10 tanks were being repaired, 6 of which came in from Borisov on August 19th. The tanks were badly damaged. Tank repair specialists were sent to the front: in July, 4 were sent to Koenigsberg, in August, 15 to Borisov.

3. New developments
  1. The Germans demand that the engine power of the tank be increased to 150 hp from 125. THis will be done with turbocharging the engine, including increasing the RPM from 2200 to 2600-2700. 500 tanks with increased engine power should be produced by the end of spring of 1942.
  2. New alloys of reduced hardness are being used for armour plates. As of March 1941, it is forbidden to use nickel in armour. As of January 1942, it will be forbidden to use nickel steel in any part of a military vehicle.
  3. Work continues on adapting the 38(t) for amphibious operation. Trials show that the tank can reach a speed of 12 kph in standing water. No drawbacks in movement and maneuverability in water were found. Currently, the propeller and its actuation mechanism are being redesigned on German orders.
  4. Production of armoured barges with tank engines should start on September 17th. 60-70 of these barges will be produced monthly.
  5. 600 5-ton half-track tractors were ordered at the factory, produced under a license from Bussing-NAG. The first 50 vehicles are due in January of 1942."

Tuesday, 20 January 2015

D-25 Reload Angles

For some reason, many people are certain that the IS-2 had to set its gun to a specific angle in order to reload. Over the years, I've heard mostly that it had to be at zero degrees, although some people insist that it had to be fully elevated, or the opposite, fully depressed. The document describing a one piece shell for the D-25 explicitly states that it could be loaded at a great range of angles, and this is using a heavier, less convenient shell. In order to fully dispel the myth, I will provide the loading and firing procedures from the IS-2 manual. This is an early manual (so early that most of it is about the IS-1, errata for the IS-2 is only provided in the very last chapter), describing the screw-breech D-25.

"2. Loading, Aiming, and Firing

The D-25 gun has a separate charge, so it is important to ensure complete ramming of the shell. In order to load the gun, do the following:
  1. Disable the inertial guard in case a shot has not been fired.
  2. Press the breech lever to disengage the breech lock from the loop on the frame.
  3. Move the lever back and to the right as far as it will go.
  4. Place the shell on the tray, disengage the tray lock, and move the tray to the cradle.
  5. Push the shell from the tray onto the guide and use the punch to ram the shell into the breech such that the driving band engages with the barrel rifling.
  6. Insert a propellant charge into the chamber.
  7. Close the breech and place the safety into the "fire" position."
As you can see, no requirement for a specific angle is given. 

Monday, 19 January 2015

AA Guns vs Ground Targets

AA guns aren't exactly ideal in an AT role. They're big and bulky, which leads to them getting spotted and destroyed. They are, however, a suitable last-ditch effort against tanks or infantry that have broken through. General Heinz Gaedcke shares my views.

DTIC A160512

But before they are found and destroyed, how well they can perform. The Flak 36 is one of the most famous guns used in this manner. Here is a penetration chart, both against armour and concrete.

Tactical and Technical Trends #8

Whoever was converting millimeters to inches must have had a long day, and this is the first time I've ever seen a 70 degree attack angle (usually it's 0 or 30 from vertical, rarely 45 or 60), but nevertheless, this is a valuable table.

The penetration of the larger 105 mm AA gun is also recorded.

Tactical and Technical Trends #30

Of course, AA guns also have HE shells as well as AP. 

Tactical and Technical Trends #40

Comparing these figures with Soviet HE, it can be seen that the increase in caliber also does not result in a large increase of shrapnel along the line of flight, instead expanding out laterally. The German 88 mm HE shell, with its burst area of ~30 by 11 meters, is inferior to the Soviet 76 mm HE shell, which manages 30 by 15 meters.

Now on to less famous weapons, low caliber automatic ones. As Gaedcke mentions, these were also used against ground targets. Here is another table with the performance of some of these guns.

PAM 30-60-1 Vol. 3 Pt. 1

This particular data is for AA guns in self propelled mounts, but towed versions also existed. The first is a Soviet weapon, mounted on the ZSU-23-4 vehicle. The second is a Czechoslovak twin AA gun. The M1A2 is an American gun (not to be confused with the M1A2 on the Sherman), which is combined with two .50 cal heavy machineguns. The last is another Soviet gun, similar to the towed S-60, but in this case there are two guns on one mount. Despite the small magazine capacity, the gun is still fully automatic.